1. Field of the Invention
The present invention relates to a photo film support device and a magnetic head securing method for the same. More particularly, the present invention relates to a photo film support device and a magnetic head securing method for the same in which a magnetic head can be precisely secured to the photo film support device with great ease.
2. Description Related to the Prior Art
A known type of photo film has a magnetic recording layer, which consists of a coating applied to a surface reverse to photographic emulsion, and to which information is magnetically recordable. Predetermined photo film information is recorded to the magnetic recording layer, and includes frame numbers, photo film sensitivity, the number of available frames, product name and the like. In taking an exposure, those kinds of information are read and used for conditioning the exposure. Also information of a particular condition determined for each exposure is recorded to the magnetic recording layer.
A camera for use with the photo film having the magnetic recording layer is provided with a magnetic head for the purpose of magnetic recording and reading. The magnetic head is fixedly secured to a photo film support plate, which supports a back surface of the photo film positioned in an exposing station, and keeps the photo film flat. For the magnetic recording and reading with the magnetic recording layer in an exact manner, it is essential to stabilize pressure in contact of the magnetic head with the magnetic recording layer.
FIG. 18 is now referred to, and the magnetic head and its relevant structure in the camera are described. The camera has an exposure aperture which defines a region to be exposed on photo film 211. There is a photo film support plate 213 or pressure plate disposed behind the exposure aperture. The photo film support plate 213 supports the photo film 211 in contact with a back surface of the photo film 211 positioned on the exposure aperture, to keep an imaging frame flat. A magnetic recording layer is formed by applying a coating of magnetic material to the back surface of the photo film 211, which is opposed to the photo film support plate 213. A magnetic head 215 is secured to the photo film support plate 213, and contacts the magnetic recording layer of the photo film 211 to record information to and/or read information from a magnetic recording area.
In FIG. 18, the magnetic head 215 is positioned to protrude forward from a head base plate 216. The photo film support plate 213 has an opening 217 through which the magnetic head 215 is disposed. The head base plate 216 is kept so positioned that the magnetic head 215 projects from the opening 217 at a predetermined projecting amount A experimentally obtained for the magnetic head 215 to give suitable pressure to the magnetic recording layer of the photo film 211. When the head base plate 216 is positioned, adhesive agent 218 is applied to the head base plate 216 and the photo film support plate 213 to extend from the rear face of the head base plate 216 to the rear face of the photo film support plate 213. The adhesive agent 218 is hardened and forms an adhesive layer in a certain spread area, to secure the head base plate 216 fixedly to the photo film support plate 213. There are plural positions on the periphery of the head base plate 216 where the adhesive agent 218 is applied.
To pour the adhesive agent 218, the head base plate 216 and the photo film support plate 213 are kept positioned with their rear directed upwards. The adhesive agent 218 is applied to overlapped portions between the head base plate 216 and the photo film support plate 213. An example of the adhesive agent 218 is an ultraviolet cure type which has a characteristic which is ordinarily fluid and hardened in response to application of ultraviolet rays.
There is a problem in the method of pouring the adhesive agent 218 on the rear faces of the photo film support plate 213 and the head base plate 216, in that the adhesive agent 218 flows to change an area where the adhesive agent 218 spreads. As the head base plate 216 itself has a relatively small area of the surface, the adhesive agent 218 comes to have an appearance giving a poor impression, because plural layers of the adhesive agent 218 overlap on one another when the adhesive agent 218 is spread on the rear of the head base plate 216. Furthermore, the spread area of the adhesive agent 218 is likely to be larger than is sufficient. The used amount of the adhesive agent 218 is wastefully large. An amount of the adhesive agent 218 to be poured for one time may be predetermined to avoid the excessive use of the adhesive agent 218. However another problem occurs in that the adhesive agent 218 is poured in an unacceptable position offset to the photo film support plate 213. A spread area defined by the adhesive agent 218 on the head base plate 216 may become extremely small, to lower the strength of fixing the head base plate 216 to the photo film support plate 213.